Heat exchangers are known in which an inlet collecting tank distributes one medium in flat heat exchanger tubes and an outlet collecting tank receives the one medium from the flat heat exchanger tubes and convey it further. The collecting tank has a wall that extends around the entire periphery of the end of a stack of heat exchanger tubes and over a certain length section of the heat exchanger tubes, the wall having at least one inlet and/or an outlet for the other medium that flows between the heat exchanger tubes. An internal insert is arranged in the flat heat exchanger tubes, which is metallically bonded to the two broad sides of the heat exchanger tube.
Published European Patent application EP 1 376 043 A2 has these features, including a collecting tank for one medium designed in one part with the collecting tank for the other medium.
A multipart configuration is shown in EP 974 804 B1, in which the collecting tank for the one medium is joined to the collecting tank for the other medium and connected together with the other parts of the heat exchanger in the soldering furnace.
Heat exchangers incorporated, for example, in an exhaust gas recirculation system of a vehicle as an exhaust heat exchanger, may be inadequate to withstand the enormous alternating temperature loads, a problems which has been generally known since the beginning of construction of heat exchangers. Numerous solution proposals and expedients therefore have been proposed and used which may provide improvements for specific applications but do not eliminate the problem.
The present invention is directed toward overcoming one or more of the problems set forth above.